Skin grafting surgery after burns

Almost every one of us has been burned at least once in our lives by boiling water, an iron, hot kitchen utensils, or an open fire. Some were “lucky” in everyday life, while others got their dose of adrenaline at work. Is it terribly painful? Of course! Is there a scar? In most cases, yes. But this is with small wound sizes. But what happens if the burn surface is significant, and skin grafting after a burn is the most effective or even the only way to solve a difficult physical, cosmetic and psychological problem?

Advantages and disadvantages of skin grafting for burns

The operation of skin grafting after a burn or other injury that has resulted in a large open wound is called skin grafting. And like any plastic surgery, it can have its advantages and disadvantages.

The main advantage of such treatment of large burn wounds is protection of the wound surface from damage and infection. Even if granulation tissue serves to protect the wound surface, it is not a full replacement for mature skin and any decrease in immunity during the wound healing process can cause serious complications.

An important aspect is that this prevents the loss of water and valuable nutrients through the uncovered surface of the wound. This is vital when it comes to large wounds.

As for the aesthetic appearance of injured skin, a wound after skin grafting looks much more attractive than a huge, frightening scar.

A disadvantage of skin grafting is the possibility of transplant rejection, which often happens when using allograft skin and other materials. If native skin is transplanted, the risk that it will not take root is significantly reduced.

Very often after skin grafting surgery, skin itching appears during the healing process, which bothers the patient. But this is a temporary phenomenon that can be prevented by using special creams.

A relative disadvantage of skin grafting can be considered psychological discomfort from the thought of transplanting someone else's skin when using allograft, xenoskin or synthetic materials.

[ 1 ], [ 2 ], [ 3 ], [ 4 ], [ 5 ]

Materials used in skin grafting

When it comes to skin grafting, a very reasonable question arises about donor material. The material for grafting can be:

• Autoskin is your own skin from an unburned area of the body that can be hidden under clothing (most often this is the skin of the inner thigh),
• Allocutaneous skin is donor skin taken from a dead person (corpse) and preserved for further use.
• Xenoskin is the skin of animals, usually pigs.
• The amnion is a protective membrane of the embryo of humans and animals that belong to higher vertebrates.

There are currently many other synthetic and natural coverings for burn wounds, but in the vast majority of cases the above materials are preferable.

When transplanting skin after a burn, biological transplants are mainly used: autoskin and allo-skin. Xenoskin, amnion, artificially grown collagen and epidermal cell transplants, as well as various synthetic materials (explants) are used mainly if temporary wound coverage is required to prevent its infection.

The choice of material often depends on the degree of the burn. Thus, for IIIB and IV degree burns, the use of an autotransplant is recommended, and for IIIA degree burns, allograft leather is preferable.

For skin grafting, 3 types of autologous skin can be used:

• pieces of donor skin that are completely separated from the body and do not communicate with other tissues of the body (free plastic surgery),
• areas of native skin that are moved and stretched over the entire surface of the wound using micro-incisions,
• a piece of skin with subcutaneous fat, connected to other tissues of the body only at one place, which is called a peduncle.

The use of the last two types is called non-free plastic surgery.

Grafts may also vary in thickness and quality:

• a thin flap (20-30 microns) includes the epidermal and basal layers of the skin. Such a transplant does not have good elasticity, can wrinkle, and is prone to damage, so it is rarely used for burns, except as temporary protection.
• flaps of medium or intermediate thickness (30-75 microns). They contain epidermal and dermal layers (completely or partially). This material has sufficient elasticity and strength, almost indistinguishable from real skin. It can be used on mobile areas, such as joints, since it does not restrict movement. Ideal for burns.
• A thick flap or a flap covering the entire thickness of the skin (50-120 microns) is used less frequently, for very deep wounds or wounds located in the visible zone, especially on the face, neck, and décolleté area. For its transplantation, it is necessary that the affected area has a sufficient number of blood vessels that connect with the capillaries of the donor flap.
• Composite transplant. A flap that includes, in addition to skin, a subcutaneous fat layer and cartilage tissue. It is used in plastic surgery for facial plastic surgery.

Intermediate skin flaps, also called split-thickness flaps, are most often used for skin grafting after burns.

Indications for the procedure

To understand this issue well, you need to remember the classification of burns by the degree of skin damage. There are 4 degrees of burn severity:

First-degree burns are small burn wounds in which only the top layer of skin (epidermis) is damaged. Such a burn is considered light (superficial, shallow) and manifests itself as pain, slight swelling and redness of the skin. Usually, it does not require special treatment, unless, of course, its area is too large.

Second-degree burns are deeper. Not only the epidermis is damaged, but also the next layer of the skin, the dermis. The burn manifests itself not only by intense redness of the affected area of skin, severe swelling and severe pain, but also by blisters filled with liquid appearing on the burned skin. If the burn surface is less than 7.5 centimeters in diameter, the burn is considered minor and often does not require medical attention, otherwise it is better to seek medical attention.

The majority of household burns are limited to I or II degree of severity, although cases of more severe injuries are not uncommon.

Third-degree burns are already considered deep and severe, since severe damage to both layers of the skin (epidermis and dermis) entails the onset of irreversible consequences in the form of tissue death. In this case, not only the skin suffers, but also the tissues underneath it (tendons, muscle tissue, bones). They are characterized by significant, sometimes unbearable pain in the affected area.

Third degree burns are divided into 2 types according to the depth of penetration and severity:

• Grade IIIA. When the skin is damaged down to the germ layer, which is externally manifested in the form of large elastic blisters with a yellowish liquid and the same bottom. There is a possibility of scab formation (yellow or white color). Sensitivity is reduced or absent.
• Stage IIIB. Complete skin damage on all its layers, the subcutaneous fat layer is also involved in the process. The same large blisters, but with a reddish (bloody) liquid and the same or whitish, sensitive to touch bottom. Brown or gray scabs are located just below the surface of healthy skin.

A fourth-degree burn is characterized by necrosis (charring) of the tissues of the affected area right down to the bones themselves with complete loss of sensitivity.

III and IV degree burns are considered deep and severe regardless of the size of the burn wound. However, indications for skin grafting after a burn most often include only IV degree and IIIB, especially if their diameter exceeds 2.5 centimeters. This is due to the fact that the lack of coverage of a large and deep wound that cannot heal on its own is a source of loss of nutrients and can even threaten the patient's death.

Burns of degree IIIA, as well as of degree II, are considered borderline. In some cases, to speed up the healing of such burn wounds and prevent their rough scarring, doctors may suggest skin grafting after the burn and in these areas, although there is no particular need for this.

[ 6 ], [ 7 ], [ 8 ]

Preparation

Skin grafting after a burn is a surgical operation, and like any surgical intervention requires certain preparation of the patient and the wound itself for skin grafting. Depending on the stage of the burn and the condition of the wound, a certain treatment is carried out (mechanical cleansing plus drug treatment) aimed at cleansing the wound from pus, removing necrotic areas (dead cells), preventing infection and the development of an inflammatory process, and, if necessary, using antibiotic therapy for their treatment.

In parallel, measures are taken to increase the body's defenses (vitamin preparations plus vitamin ointment dressings, general tonics).

A few days before the operation, local antibiotics and antiseptics are prescribed: antiseptic baths with potassium permanganate or other antiseptic solutions, dressings with penicillin or furacilin ointment, as well as UV irradiation of the wound. The use of ointment dressings is stopped 3-4 days before the expected date of the operation, since ointment particles remaining in the wound will interfere with the engraftment of the transplant.

Patients are prescribed a complete protein diet. Sometimes blood or plasma transfusions are performed. The patient's weight is monitored, laboratory test results are studied, and drugs for anesthesia are selected.

Immediately before the operation, especially if it is performed under general anesthesia, it is necessary to take measures to cleanse the intestines. At the same time, you will have to refrain from drinking and eating.

If the transplant is performed in the first days after the injury on a clean burn wound, it is called primary and does not require careful measures to prepare for the operation. Secondary transplant, which follows a 3-4 month course of therapy, requires mandatory preparation for the operation using the above methods and means.

The issue of anesthesia is also resolved at the preparatory stage. If a relatively small area of skin is being transplanted or a wound is excised, local anesthesia is sufficient. For extensive and deep wounds, doctors tend to use general anesthesia. In addition, doctors must be prepared for a blood transfusion, if needed.

[ 9 ], [ 10 ], [ 11 ], [ 12 ]

Technique skin grafts after a burn

The stages of the skin transplant operation after a burn depend on the material used by the plastic surgeon. If autoskin is used, then the first step is to collect donor material. And in the case where other types of transplants are used, including preserved biological ones, this point is omitted.

The collection of autografts (excision of skin flaps of the required thickness and size) was previously carried out mainly with a scalpel or a special knife for skin, but at present surgeons prefer dermatomes as a convenient and easy-to-use instrument that significantly facilitates the work of doctors. It is especially useful when transplanting large skin flaps.

Before you begin excising the donor skin, you need to decide on the size of the flap, which should exactly match the contours of the burn wound where the skin will be transplanted. To ensure complete matching, an X-ray or regular cellophane film is applied to the wound and the wound is outlined, after which the finished "stencil" is transferred to the area where it is planned to take the donor skin.

Skin for transplantation can be taken from any area of the body of a suitable size, trying to avoid those areas that cannot be covered with clothing. Most often, the choice falls on the outer or back surfaces of the thighs, the back and buttocks. The thickness of the skin is also taken into account.

After the doctor has decided on the donor area, the skin is prepared for excision. The skin in this area is washed with a 5% soap solution (gasoline can also be used), after which it is carefully treated with medical alcohol several times. Using a scalpel/knife (for small areas) or a dermatome (for large flaps), a suitable flap of the required thickness, uniform over the entire surface, is cut out using a “template”.

At the site of the cut, a wound with minor bleeding is formed, which is treated with hemostatic and antiseptic agents, after which an aseptic bandage is applied to it. The wounds at the donor site are shallow, so the healing process generally occurs quickly and without complications.

Skin grafting after a burn also involves preparing the burn wound. It may require cleaning the wound, removing necrotic tissue, performing hemostasis, leveling the wound bed, and excising hardened scars along the edges of the wound.

The excised autograft is immediately placed on the prepared wound surface, carefully aligning the edges, and pressed evenly with gauze for a couple of minutes, preventing the flap from moving. Flaps of medium thickness can be secured with catgut. A pressure bandage is applied on top.

For good fixation of the skin flap, a mixture of fibrin (or plasma) solution with penicillin can be used.

If the skin is transplanted to a small area, the skin flaps are taken whole, but if the wound surface is of significant size, several flaps are applied or a special transplant with micro-incisions is used, which can be significantly stretched and aligned to the size of the wound (perforated transplant).

Skin grafting using a dermatome

The skin transplant operation after a burn begins with the preparation of the dermatome. The side surface of the cylinder is covered with a special glue, when it dries slightly after a couple of minutes, the lubricated surface is covered with a gauze napkin. When the gauze sticks, the excess edges are cut off, after which the dermatome is sterilized.

Approximately half an hour before the operation, the dermatome knives are treated with alcohol and dried. The area of skin from which the donor flap will be taken is also wiped with alcohol and left to dry. The surface of the dermatome knives (with gauze) and the desired area of skin are covered with dermatome glue.

After 3-5 minutes, the glue will dry sufficiently, and you can begin excising the donor skin flap. To do this, the dermatome cylinder is pressed tightly to the skin, and when it sticks, the dermatome is lifted slightly, starting to cut the skin flap. The knives, with a rhythmic movement, cut the flap, which is carefully placed on the rotating cylinder. After the desired size of the skin flap is reached, it is cut with a scalpel. The autograft is carefully removed from the dermatome cylinder and transferred to the wound surface.

Allograft transplantation

If skin grafting after a burn is aimed at closing the wound for a long period, it is advisable to use autografts. If temporary wound coverage is required, the best option for this is grafting preserved cadaver skin.

Of course, it is possible to use donor skin, for example, flaps from amputated limbs. But such a covering is quickly rejected, not giving the wound full protection from damage and infection.

Properly preserved allo-skin is rejected much later. It is an excellent alternative to autotransplants if it is not possible to use them due to a shortage of donor skin. And allo-skin transplantation often makes it possible to save the patient's life.

The operation to transplant allo-skin does not cause any particular difficulties. The burn surface is cleaned of pus and necrotic tissue, washed with an antiseptic solution and irrigated with an antibiotic solution. Allo-skin is applied to the prepared wound, having previously soaked it in a physiological solution with the addition of penicillin, and secured with infrequent stitches.

Contraindications to the procedure

Although skin grafting after a burn may seem harmless and relatively easy compared to other surgical interventions, there are situations in which such manipulations are unacceptable. Some of them are associated with insufficient readiness of the wound for skin grafting, and others - with pathologies of the patient's health.

Skin grafting after a burn is performed around 3-4 weeks after the injury. This is because after 20-25 days the wound is usually covered with granulation tissue, which from the outside looks like a granular surface with a large number of blood vessels of a rich pink color. This is young connective tissue that forms in the second stage of healing of any wound.

Skin grafting on large areas and in case of deep burns cannot be done until the skin is completely cleared of "dead" cells and granulation tissue has formed. If the young tissue is pale and the areas are necrotic, skin grafting will have to be postponed until after the excision of the weak tissue, strong new tissue forms in its place.

If the wound is quite small in size and has clear, even outlines, wound cleaning and skin grafting surgery are not prohibited even in the first days after the injury, without waiting for the development of symptoms of secondary inflammation.

Skin grafting is prohibited if there are signs of inflammation, wound exudate or purulent discharge in and around the wound, which most likely indicates the presence of infection in the wound.

Relative contraindications to skin grafting include poor patient condition at the time of preparation for surgery, such as shock, major blood loss, exhaustion, anemia, and unsatisfactory blood tests.

Although skin grafting is not a very complex operation and takes only about 15-60 minutes, it is necessary to take into account the significant pain of such manipulation, as a result of which it is carried out under local or general anesthesia. Intolerance to drugs used in anesthesia is also a relative contraindication to skin grafting surgery after a burn.

[ 13 ], [ 14 ], [ 15 ], [ 16 ]

Complications after the procedure

Correct timing of the operation, careful and effective preparation for skin grafting after a burn, and proper care of the transplanted skin are the main conditions for a successful operation and help prevent unpleasant consequences. And yet, sometimes the patient's body, for some reasons understandable only to it, does not want to accept even the native skin, considering it a foreign substance, and simply melts it.

The same kind of complications can be caused by incorrect preparation of the wound for surgery if pus and dead skin cells remain in the wound.

Sometimes there is rejection of transplanted skin, which manifests itself as its complete or partial necrosis. In the latter case, a second operation is indicated after removing the transplanted and non-grafted skin flap. If the necrosis is partial, only dead cells should be removed, leaving those that have taken root.

The skin does not always take root quickly, sometimes this process takes a couple of months, although it usually takes 7-10 days. In some cases, postoperative sutures begin to bleed. If there is insufficient sterility during the operation or poor preoperative preparation, additional infection of the wound may occur.

In some cases, after a successful operation and healing of the transplanted skin, unexplained ulcers may appear on it, or a thickening of the surgical scar (the junction of healthy and donor skin) may be observed, as well as a lack of normal hair growth and decreased sensitivity in the grafted area of skin.

The unfortunate consequences of the wrong choice of material for transplantation and untimely surgery can be damage (cracking) of the transplanted skin, as well as limited movement (contraction) in the joint where the skin graft was performed after a burn.

[ 17 ], [ 18 ], [ 19 ], [ 20 ]

Care after the procedure

Restoration of the skin after skin grafting after a burn occurs in 3 stages. From the moment the skin grafting operation is completed, the combined skin adapts within 2 days, after which the skin regeneration process begins, which lasts about 3 months.

During this time, it is necessary to protect the area with the transplanted skin from mechanical and thermal damage. The bandage can be removed no earlier than the doctor allows.

In the first period after removing the bandage, it is recommended to take medications that reduce pain, if necessary, as well as lubricate the young skin of the transplant with special ointments that prevent it from drying out and peeling, and also relieve skin itching (cold paste, lanolin ointment and other medications that ensure the maintenance of sufficient tissue moisture).

Once the regenerative changes are complete, the stabilization process begins, when no special measures for the care of the transplanted skin are required. The beginning of the stabilization process indicates with great confidence that the skin transplant after a burn was successful.

Rehabilitation period

At the end of the skin grafting operation after a burn, it is necessary to ensure good adhesion of the thoracic graft to the wound bed. To do this, carefully squeeze out the remaining blood so that it does not interfere with the adhesion of the tissues.

Sometimes the graft is secured with stretch sutures (for example, in the case of a perforated flap). If the graft is secured with threads, their edges are left uncut. Wet cotton balls are placed on top of the transplanted skin flap, then cotton swabs and pulled tightly with the free ends of the thread.

To prevent rejection of transplanted flaps, the dressings are irrigated with glucocorticosteroid solutions.

Usually, the transplant takes 5-7 days to take root. During this time, the bandage is not removed. After a week, the doctor examines the wound, removing only the upper layers of the bandage. The question of the first dressing is decided on an individual basis. Everything depends on the patient's condition after the operation. If the bandage is dry, the patient has no fever or swelling, only the wound is bandaged.

If the bandage is wet, there is no need to worry prematurely. This happens due to the accumulation of wound exudate under the graft. Sometimes it is enough to simply release it and re-fix the graft with a bandage. If blood or pus comes out from under the graft, there is a high probability that it will not take root.

If necessary, the first dressing is prescribed, during which the tissues that have not taken hold are removed. After which a new skin grafting operation is performed.

If all goes well, the graft will fuse with the skin within 12-14 days. After the bandage is removed, it will appear pale and unevenly colored, but after a while it will acquire a normal pink hue.

If for some reason a bandage is not applied after surgery, it is necessary to protect the transplanted area from damage (for example, using a wire frame).

[ 21 ]